The present invention relates to a fire extinguisher and, more particularly, to a fire extinguisher with a more reliable structure preventing powder from overflowing out of the fire extinguisher.
A type of conventional fire extinguisher generally includes a pressurized barrel receiving fire extinguishing powder. A guiding tube is mounted in the barrel and is connected to an outlet of the barrel. A piston valve is mounted in the guiding tube and is connected to a spring. The piston valve can be actuated by a pressing rod mounted on top of the barrel. A safety pin is mounted to the pressing rod. In use, the safety pin is removed, and the pressing rod is moved downward to open the piston valve. The powder in the barrel can be rapidly discharged via the guiding tube and the outlet under action of the air pressure in the barrel.
To avoid adverse influence on movement of the piston valve resulting from accumulation of the powder in the position of the spring, the above fire extinguisher must be placed upright when not in use. However, when the fire extinguisher is placed in a car or an unfixed position, it is difficult to maintain the fire extinguisher in the upright position, and the pressing rod could be inadvertently actuated by shock.
Another type of fire extinguisher includes an external high pressure steel bottle fixed to the barrel. The barrel receives fire extinguishing powder, and a piston valve is mounted in an outlet of the barrel. A firing pin and a switch are mounted to the barrel in a position corresponding to the steel bottle. Before the high pressure steel bottle is opened, the barrel does not have high pressure because the piston valve blocks the passage where the outlet is located. However, when the fire extinguisher is not placed upright or the fire extinguisher is placed in a car and is subjected to shock, the piston valve is apt to displace and cause overflow of the powder.